The upright posture of plants is a striking design that falls short of a clear explanation. The pat answer is that prehistoric flat plants decided to go vertical to compete for more sun. But where did this need to compete arise? And how could a limp ground hugger accidentally develop systems to support excessive weight — maybe tons of wood — root systems to support the weight, transport systems to move the water and nutrients up, and defense mechanisms against weather and pests? Much of it had to be there at the same time. An analogy that I used in my previous book readily applies. The spontaneous appearance of an upright plant would be like taking a walk from New York City to Los Angeles and then pointing out how easy it was because your first step took you to Cleveland and the second one to Chicago.

The adhesive used by barnacles is among the strongest in the world. It is reported that a layer merely 3/10,000 of an inch thick can support a weight of 7000 pounds. This relative of the shrimp and crab glues its head down and keeps its feet up to catch the next meal. Its adhesive sets in water at any temperature and will not dissolve in most acids, bases, and solvents. Fossil records suggest it has been used by barnacles unchanged for 400 million years. Nothing seems to be known about its intermediates before that.

Mussels have a similar glue, which sets underwater and has enormous strength. It takes about five minutes for the mussel to create a “dab” of this glue beneath its foot on a piling or rock. Twenty dabs will do it, and the job can be completed overnight. Imagine the consternation of intermediate species when they secreted what they thought was glue, but kept being washed away by the waves. Or the species that couldn’t store their glue and found their bivalves stuck together.

A design must be considered improbable if it is highly functional and durable yet too complex to have come about spontaneously or by intermediate steps. Think of the subway system in any large metropolitan area. Could the combination of tracks, stations, tunnels, signs, vending machines, stairwells, lighting, trains, billboards, ticket booths, turnstiles, benches, platforms, security measures, and restrooms have happened all at once or did it come about by stages? If these commuter systems were to follow the tenets of the theory of evolution, the tracks going off in every direction might be called links to the stations called species. How does one get from station to station without the tunnel, train, and tracks? In the theory of evolution, these kinds of intermediaries are abundantly missing.

The wombat has an upside-down pouch. Scientists presume, and it makes sense, that position prevents dirt from entering the pouch when the wombat is digging in the ground. Could there have been transitional species with pouches situated sideways, or did the first wombats have to scoop dirt out of their pouches every day?

When it comes to citing examples of purposeful design, nearly every author likes to point out the hen’s egg. It’s really quite remarkable. Despite having a shell that is a mere 0.35 mm think, they don’t break when a parent sits on them. According to Dr. Knut Schmidt-Nielsen,

A bird egg is a mechanical structure strong enough to hold a chick securely during development, yet weak enough to break out of. The shell must let oxygen in and carbon dioxide out, yet be sufficiently impermeable to water to keep the contents from drying out.

Under microscopy, one can see the shell is a foamlike structure that resists cracking. Gases and water pass through 10,000 pores that average 17 micrometers in diameter. Ultimately, 6 liters of oxygen will have been taken in and 4.5 liters of carbon dioxide given off. The yolk is its food. All life support systems are self-contained, like a space shuttle.

All hen’s eggs are ready to hatch on the twenty-first day. Every day is precisely preprogrammed. The heart starts beating on the sixth day. On the nineteenth day the embryo uses its egg tooth to puncture the air sac (beneath the flat end) and then takes two days to crack through the shell.

Velvet worms are thought to be descended of insects, but the evidence for this is scanty; they look a lot like worms, and they have remained unchanged for millions of years. They live along fallen leaves in tropical forests and have two nozzles, one on each side of their head, which can fire off a very quickly drying glue at their prey. These two sprays crisscross back and forth, as if lassoing the victim. Once the victim is securely ensnared, the worm bites a hole in its body, injects digestive juices, and then slurps up the dissolving victim. Curiously, this glue does not dry within the worm’s body, and its digestive juices are well contained. Imagine the difficulty if the intermediate glue dried within the velvet worm, clogging the nozzles, or dried too slowly, allowing the victim to get away before becoming ensnared.